A large number of generally planar objects such as compact disks, floppy disks, optical cartridges, and semiconductor wafers are manufactured and handled using processes which require lifting a single one of such objects from a plurality in a vertical stack. Such objects are selected or picked in preparation for moving or transporting the object during the manufacturing or other operational processes. In addition, users of such objects may employ similar picking or selecting devices in handling and moving objects during use and/or storage. In many instances, the processes involved are repetitive as, for example, is found in transferring a plurality of objects from a stack to one or more alternate positions or locations.
One of the most common types of planar objects of the type to which the present invention pertains is found in the various data storage media for computer systems. For example, the well known and pervasive compact disk which has found great use in data storage for computer, video and audio systems provides a medium which is generally planar and circular and which defines a center hole. In most compact disk media use, a plurality of laser embossed circular tracks are provided on the underside of the compact disk to store data. Other similar devices such as the well known floppy disk which provides magnetic media as well as optical cartridges which provide optically encoded data are similar in that they are generally planar media defining a center hole.
In virtually all processes involving such planar objects, handling by humans, even utilizing precautionary gloves and garments etc., is potentially damaging to such objects and is, for the most part, far too expensive with respect to labor costs. As a result, manufacturers and users of such planar devices employ machine handlers which mechanically grasp and handle such objects. Handling machines require a device or mechanism for attachment to the object. Such attachment or grasping devices are often referred to in the art as "pickers" due to their function of grasping or "picking" a single object from a plurality or stack of objects. For the most part, these picker devices are vacuum or suction-operated making use of the top surface portion of the media objects for attachment. Thus, in a typical vacuum or suction operated picker unit, a plurality of flexible soft suction cups are coupled to a vacuum source and a valving body operative under appropriate control for applying partial vacuum to the suction cups during the picking operation. A transport mechanism usually mechanical in operation is provided to move the picker unit between the location of the stack and the alternate location to which the media devices or objects are to be transported. While vacuum or suction-operated pickers form the major part of such devices in use, practitioners in the art have attempted to employ other mechanical attachments which utilize the outer edges of the planar objects for mechanical grasping.
While the prior art picking devices such as those referred to above have provided some operational capability within the art, there remains nonetheless a continuing need in the art for a lower cost, simpler, more reliable and more effective picker device for use in attachment to planar objects such as compact disk or other media.